Cost is an important parameter in optical Local Area Networks (LANs) and Metropolitan Area Networks (MANs). The cost of lasers is a prime component of the costs in such networks. Also, the Carrier Sense Multiple Access with Collision Detection (CSMA/CD) protocols (e.g., Ethernet, IEEE 802.3, etc.) of traditional LANs may not readily be adopted for optical LAN/WANs because of the longer distances involved.
What is desired is an optical LAN/MAN network where multiple users can share the same laser source and at the same time provide an efficient way of allocating bandwidth among users.